Refrigerating apparatus



Jan. 29, 1963 w. K. STEINHAGEN 3,075,686

REFRIGERATING APPARATUS Filed Nov. 20, 1957 3 Sheets-Sheet l V INV ENTOR.

ll [Ilium A. Szeinbgyen HIS ATTORNEY Jan, 29, 1963 w. K. STEINHAGEN3,075,686

REFRIGERATING APPARATUS Filed Nov. 20, 1957 3 Sheets-Sheet 2 INVENTOR.ll/illian [If Sleinhgyen H IS ATTORNEY Jan. 29, 1963 w. K. STEINHAGEN3,075,686

REFRIGERATING APPARATUS 3 Sheets-Sheet 3 Filed Nov. 20, 1957 INVENTOR.William K. Szeinba HIS ATTORNEY United States Patent Ofifice 3,075,686Patented Jan. 29, 1963 3,075,686 REFRIGERATING APPARATUS William K.Steinhagen, Royal Oak, Mich, assignor to General Motors Corporation,Detroit, Mich, a corporation of Delaware Filed Nov. 20, 1957, Ser. No.697,575 2 Claims. (Cl. 230-58) This invention relates to refrigeratingapparatus and more particularly to a sealed motor-compressor unit.

It is an object of this invention to provide an improved arrangement forvarying the stroke of a reciprocating compressor by means of a doubleeccentric arrangement.

It is customary to manufacture refrigerators of various sizes and toequip the different sized refrigerators with a compressor of a sizesuitable for each refrigerator and this usually necessitatesmanufacturing a number of different size compressors. It has been theusual practice to accomplish this result by changing either the bore orstroke or both of the compressor and changing many associated partswhereby these parts are not usable in more than one size compressor. Itis an object of this invention to keep as many parts as possiblecompletely interchangeable among the various size compressors so thatexcept for the motor it is only necessary to change the size of a spacerwhich determines the clearance between the piston and the cylinder head.

Further objects and advantages of the present invention will be apparentfro-m the following description, reference being had to the accompanyingdrawings, wherein a preferred form of the present invention is clearlyshown.

In the drawings:

FIGURE 1 is a vertical sectional view showing a preferred embodiment ofthe invention;

FIGURE 2 is a horizontal sectional view taken substantially on line 22of FIGURE 1;

FIGURE 3 is a vertical sectional view taken substantially on the line3-3 of FIGURE 1;

FIGURE 4 is a fragmentary vertical sectional view taken substantially online 4-4 of FIGURE 1 and showing the suction valve arrangement;

FIGURE 5 is a fragmentary sectional view taken on line 5-5 of FIGURE 1and showing one possible arrangement of the dual eccentrics for maximumstroke of the piston;

FIGURE 6 is a view similar to FIGURE 5 but showing another possiblearrangement of the dual eccentrics which would give a minimum pistonstroke;

FIGURE 7 is a fragmentary end elevational view showing the constructionof the cylinder head cover plate;

FIGURE 8 is a fragmentary sectional view taken substantially on the line8-8 of FIGURE 3 and showing the discharge reed valve; and

FIGURE 9 is a fragmentary sectional view on an enlarged scale showing insomewhat exaggerated manner the curvature of the piston.

Referring now to the drawings wherein a preferred embodiment of theinvention has been shown, reference numeral 10 designates an invertedcup-shaped casing element which in cooperation with an end plate 11forms a sealed motor-compressor housing. The end plate 11 is in the formof a sheet metal stamping having upwardly extending embossed portions 12which serve as seats for coil springs 14 used in supporting themotor-compressor mechanism within the main housing 10.

The motor-compressor mechanism includes a stamped sheet metal frameelement 16 which has brazed or otherwise secured thereto a plurality ofU-shaped stampings 18 to which there are secured spring engaging studs20 as best shown in FIGURE 1. The studs 20 project on into the springs14 so as to position and support the motorcompressor unit within themain casing. The stamped sheet metal frame element 16 has securedthereto a sheet metal sleeve element 24 which serves to support a castiron bearing sleeve 26 in which the main drive shaft 28 is journalled. Aconventional motor stator 30 is held in place on the stamped frameelement 16 by means of a cylindrical sheet metal stator supporting ring32 which is secured to the frame 16.

A motor rotor assembly 34 is secured to the upper end of the shaft 28through the medium of the sleeve element 36. The upper end of the motorrotor 34 is provided with integrally formed fan blade elements 38 whichare cast as integral parts of the usual rotor end ring. The lower end ofthe shaft 28 is provided with an eccentric portion 40 which is smallerin diameter than the main portion of the shaft 28. This reduced endportion 40 serves to support a ring-like .element 42 having an eccentricaperture through which the eccentric portion of the shaft 40 projects soas to form therewith a double eccentric. The element 42 has a press fiton the portion 40 so as to prevent relative rotation of the parts afterthey have been assembled in the desired relationship. The ring-likeelement may be assembled onto the eccentric end portion 40 of the maindrive shaft in any of many relative positions whereby it is possible toobtain many different overall effective eccentricities without changingthe size of the individual parts. Thus it is possible to obtaindifferent length piston strokes and therefore different compressorcapacities by changing the relative position of the parts when the partsare first assembled.

A ring 44 is rotatably mounted on the outer periphery of the eccentricportion 42 and is adapted to engage the one end member 50 of a pistonassembly generally designated by the reference numeral 52. There is aslight curvature on the end member 50 so as to eliminate the need forsquareness or alignment. The ring 44 which is free to rotate on theeccentric portion 42 engages the curved surface on the member 50 with arolling action so as to reduce the wear on the engaging surface. Thepiston assembly 52 includes a substantially cup-shaped sheet metalstamping 54 which is brazed or otherwise secured to the thrust member 50as best shown in FIG- URES 1 and 2.

The piston element 54 is sliclably supported within a fixed cylinderelement 56 carried by and secured to the sheet metal frame elements 16by means of bolts 57. A coil spring 55 is provided between end plate 50of the piston assembly 52 and a shoulder 59 provided on the cylinderelement 56 so as to bias the piston assembly towards the eccentric onthe main drive shaft. By virtue of the above described arrangement,rotation of the drive shaft 28 will cause the eccentrically mounted ring44 to actuate the piston assembly. A valve plate 61 having an inlet port64 and an outlet port 65 closes the one end of the cylinder element asshown. The gas to be compressed enters the housing 10 through thesuction line 58 which enters the housing 10 as best shown in FIGURE 1.

A sheet metal deflector element '60 is provided as shown adjacent theinlet line 58 so as to largely prevent intermingling of the relativelycold incoming refrigerant vapor and the relatively hot refrigerant vaporsurrounding the motor. A conduit 62 directs the incoming refrigerantdownwardly to the suction inlet 64 leading to the compression chamberWithin the cylinder element 56.

A reed type valve plate 70 is provided between the valve plate 61 andthe end wall of the cylinder 56. This valve plate is best shown inFIGURE 4 and includes an inlet valve reed portion 72 which serves theusual function of an inlet valve. A reed valve 74 (see FIGURE 8) isprovided for controlling the flow through the discharge port 65 inaccordance with well known practice. A

stamped" sheet metal plate 76 is brazed to a plate element 78 and thisassembly is held in place as best shown in FIGURE 1 against the valveplate 61. The gas to be compressed is supplied to the compressionchamber through the conduit 62' which leads. to the suction port 64 andthe compressed gas is delivered into a muffier chamber 80 via a passage82 formed between the embossed metal plate. 76 and the plate element 78.The gas. leaves the. mother chamber through the outlet line 84.

When each compressor is first assembled the relative position of theeccentric ring-like portion 4 2 on the eccentric portion 40 of the driveshaft will be fixed so as to provide the desired piston. stroke for acompressor of a given desired output rating. The desired head clearancein the compression chamber for any given length of stroke is obtained byselecting a spacer or shim element 90 having a thickness which willestablish the desired relationship between the shaft 28 and the cylinderhead which in this case includes the valve plate 61 and associatedparts.

In this manner it is possible to make compressors of several differentcapacities, all of which use the same basic compressor parts except forthe thickness of the spacer shim 90.

While the form of embodiment of the invention as herein disclosedconstitutes a preferred form, it is to be understood that other formsmight be adopted, as may come within the scope of the claims whichfollow.

What is claimed isas follows:

1. In a sealed motor-compressor unit, an inverted cupshaped stampedsheet metal casing, a stamped sheet metal base plate for closing theopen end of said casing, said plate having a plurality of inwardlyembossed spring seats formed thereon, a motor-compressor assemblydisposed within said casing, said assembly including a stamped sheetmetal frame element, spring seats carried by said stamped frame elementand arranged substantially in vertical alignment with said embossedspring seats, spring members disposed between said vertically alignedspring seats, said stamped sheet metal frame element having securedthereto a bearing element, a shaft rotatably disposed within saidbearing element, a motor including a rotor secured to one end of saidshaft, said shaft having an eccentric portion formed thereon, ring meansdisposed on said eccentric portion, said ring means having an aperturethrough which said eccentric portion projects, said aperture beingoffset from the center of said ring means, said ring means having apress fit on said eccentric portion whereby the relativeposition of saidring on said eccentric portion. when assembled determines the overalleffective eccentricity of the outer periphery of said ring means,cylinder means carried by said frame element, a reciprocating pistonoperated by said eccentric portion and dis posed within said cylindermeans, said piston including a portion arranged to directly engage saidring means so as to be reciprocated thereby.

2. In a sealed motor-compressor unit, a sheet metal casing, amotor-compressor assembly disposed within said casing, said assemblyincluding sheet metal frame means,- said frame means including a shaftbearing, a shaft rotatably disposed within said bearing, a motorincluding a rotor secured to one end of said shaft, said shaft having aneccentric portion formed thereon, ring means disposed on said eccentricportion and held thereon in any one of several possible relativepositions of said eccentric portion and said ring means, said ring meanshaving an aperture through which said eccentric portion projects, saidaperture being offset from the center of said ring means, cylinder meanscarried by said sheet metal frame means and including a compressionchamber, a reciprocating piston means disposed within said chamber, saidpiston means including a portion having a slightly curved cam surfacearranged to. directly engage said ring means so as to be reciprocatedthereby, means for positioning said cylinder means in a predeterminedrelationship. relative to the central axis of said shaft, said lastnamed means comprising a shim between a portion of said frame means anda portion of said cylinder means for establishing the distance betweenthe end of said compression chamber and the center of rotation of saidshaft. 8

References Cited in the file of this patent UNITED STATES PATENTS1,026,132 Thompson May 14, 1912 1,091,496 Fox Mar. 31, 1914 1,761,429Dean June 3, 1930 1,772,667 Hvid Aug. 12, 1930 1,901,817 Neidl Mar.14,1933 2,040,667 Moulet May 12, 1936 2,312,057 Williams Feb. 23, 19432,328,420 Brown et al Aug. 31, 1943 2,414,003 Thompson Jan. 7, 19472,472,355 Whittingham June 7, 1 949 2,500,751 Halvarson Mar. 14, 19502,587,246 Touborg Feb. 26, 1952 2,592,237 Bradley Apr. 8, 1952 2,622,788Ramclow Dec. 23, 1952 2,693,150 Pickard et al. Nov. 2, 1954 2,766,929Rusch et al Oct. 16, 1956 2,783,615 Gooch et al Mar..5, 1957 2,823,850Hintze Feb. 18, 1958 2,842,284 Flick July 8, 1958 2,945,451 GriswoldJuly 19, 1960 FOREIGN PATENTS 600,415 Great Britain July 6, 1946 505,533Belgium Aug. 30, 1951 567,840 Canada Dec. 15., 1953 1,126,864 FranceDec. 3, 1956 OTHER REFERENCES German application KL 59a35, P-11,505,August 9, 1956.

1. IN A SEALED MOTOR-COMPRESSOR UNIT, AN INVERTED CUPSHAPED STAMPEDSHEET METAL CASING, A STAMPED SHEET METAL BASE PLATE FOR CLOSING THEOPEN END OF SAID CASING, SAID PLATE HAVING A PLURALITY OF INWARDLYEMBOSSED SPRING SEATS FORMED THEREON, A MOTOR-COMPRESSOR ASSEMBLYDISPOSED WITHIN SAID CASING, SAID ASSEMBLY INCLUDING A STAMPED SHEETMETAL FRAME ELEMENT, SPRING SEATS CARRIED BY SAID STAMPED FRAME ELEMENTAND ARRANGED SUBSTANTIALLY IN VERTICAL ALIGNMENT WITH SAID EMBOSSEDSPRING SEATS, SPRING MEMBERS DISPOSED BETWEEN SAID VERTICALLY ALIGNEDSPRING SEATS, SAID STAMPED SHEET METAL FRAME ELEMENT HAVING SECUREDTHERETO A BEARING ELEMENT, A SHAFT ROTATABLY DISPOSED WITHIN SAIDBEARING ELEMENT, A MOTOR INCLUDING A ROTOR SECURED TO ONE END OF SAIDSHAFT, SAID SHAFT HAVING AN ECCENTRIC PORTION FORMED THEREON, RING MEANSDISPOSED ON SAID ECCENTRIC PORTION, SAID RING MEANS HAVING AN APERTURETHROUGH WHICH SAID ECCENTRIC PORTION PROJECTS, SAID APERTURE BEINGOFFSET FROM THE CENTER OF SAID RING MEANS, SAID RING MEANS HAVING APRESS FIT ON SAID ECCENTRIC PORTION WHEREBY THE RELATIVE POSITION OFSAID RING ON SAID ECCENTRIC PORTION WHEN ASSEMBLED DETERMINES THEOVERALL EFFECTIVE ECCENTRICITY OF THE OUTER PERIPHERY OF SAID RINGMEANS, CYLINDER MEANS CARRIED BY SAID FRAME ELEMENT, A RECIPROCATINGPISTON OPERATED BY SAID ECCENTRIC PORTION AND DISPOSED WITHIN SAIDCYLINDER MEANS, SAID PISTON INCLUDING A PORTION ARRANGED TO DIRECTLYENGAGE SAID RING MEANS SO AS TO BE RECIPROCATED THEREBY.